Reliability assessment and validation of the dermal pigmentation area and severity index: a new scoring method for acquired dermal macular hyperpigmentation.

BACKGROUND

Dermal pigmentation area and severity score (DPASI) is a recently proposed scoring system for acquired dermal macular hyperpigmentation (ADMH).

OBJECTIVE

To determine the reliability and validity of DPASI.

METHODS

After standardized training, three researchers independently rated 55 patients with ADMH on two consecutive days within 1 week, to determine intra-rater and inter-rater reliability. Validation was performed by comparing DPASI with the physician global assessment score.

RESULTS

Test-retest reliability of individual raters tested by Pearson's r showed good correlation for all three raters (r = 0.984, P < 0.0001; r = 0.983, P < 0.000 and r = 0.970, P < 0.0001). Inter-rater agreement computed by intra-class correlation coefficient also showed good correlation (ICC = 0.997, P < 0.0001). Internal consistency as measured by Cronbach's alpha was 0.997. The score faired well in face and content validity (I-CVI of 0.87). On usability assessment, the scale had a median score of 4 on a scale from 1 to 5. The meantime taken to score the patients were 307.2 ± 83, 308.9 ± 84.4, 350.15 ± 91.8 s by three observers, respectively.

CONCLUSION

The DPASI is a reliable measure of ADMH severity. The use of dermoscopy decreases inter and intra-observer variation resulting in a more objective score.